This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. Primary support for the subproject and the subproject's principal investigator may have been provided by other sources, including other NIH sources. The Total Cost listed for the subproject likely represents the estimated amount of Center infrastructure utilized by the subproject, not direct funding provided by the NCRR grant to the subproject or subproject staff. Early ovarian failure and infertility are well-known side effects of anti-cancer treatments. Attempts to preserve fertility and ovarian function in female cancer patients have met with little success. In mice, sphingosine-1-phosphate (S1P), a metabolite of the pro-apoptotic stress sensor ceramide, protects the ovaries from radiation-induced damage in vivo, preserves a normal level of fertility, and offspring conceived with oocytes protected from radiation by S1P show no evidence of transgenerational genomic damage. The safety and efficacy of S1P for preserving ovarian function and fertility in primates exposed to anti-cancer treatments needs to be established. Technologies to deliver S1P only to the ovaries, thereby preventing systemic availability of S1P that could benefit the tumor cells targeted for destruction, also requires validation. The specific aims are 1) to determine if S1P can be administered directly into the rhesus monkey ovary to protect the gonads from radiotherapy-induced damage in vivo;2) to evaluate the competency of macaque oocytes protected from radiotherapy by S1P for fertilization and embryogenesis;and 3) to assess if offspring conceived from macaque oocytes protected from radiotherapy by S1P in vivo show evidence of propagated genomic damage. Five live, normal offspring were derived from S1P agonist-treated females who received ovarian X-irradiation. They are now 1-2 years old and will be maintained until puberty and then mated to assess whether the second generation is free from genomic damage. Thus, S1P has potential as a safe and effective strategy for protecting human ovaries from the damage caused by anti-cancer therapies, and prevent infertility.